Not applicable.
Not applicable.
1. Field of the Invention
This invention relates in general to a conveyor guiderail snag resistant opening and, more particularly, to a conveyor guiderail snag resistant opening for use in devices which transport irregular items such as bundled newspapers or newsprint.
2. Description of Related Art
Automated conveying systems normally utilize some form of sensing device to detect the presence of transported articles on the conveying system. While lever operated switches can be used as the sensing device for these systems, optical switches represent the type of sensing device used on a wide variety of conveying systems. When such optical sensing switches are used, the guiderails of the conveyor assembly usually have openings through which optical sensing devices may transmit and receive optical signals.
Prior art teaches that the opening for such optical sensing devices may be of any shape as long as the opening allows the communication of an optical signal across the conveyor track. In most cases, the size and shape of the sensor openings are simply round, square, or elliptical, and are sized such as to allow optical communication. These types of openings are also simply placed into the guiderails of conveyor systems by punching holes in the guiderails. This type of fabrication results in a sensor opening where all edges of the opening are flush with the inside surface of the guiderail. That is, the entire perimeter of the sensor opening is on the surface of the guiderail and no portion of the sensor opening is depressed into the surface of the guiderail.
When the conveyor is transporting boxes or other types of packaged items, these types of square, round, or elliptical openings that are made flush with the inside surface of the guiderail do not interfere with the movement of those items on the conveyor system and do not damage the transported items. However, these types of openings are prone to cause damage to certain irregular items being transported on a conveying system. In particular, the transport of stacks of newspaper and other such items on conveying systems which have square, round, or elliptical openings will cause the sharp edges of those openings to snag the paper in the bundle.
An example of this problem is found in the transport of newspaper material on a conveyor system. In that situation, the newsprint is susceptible to catching and tearing. Additionally, the newspapers on the conveyor system are placed on the conveyor such that the edges of the newspaper will often be against the guiderails of the conveyor. There is a tendency for the edges of the newspaper bundles or protruding corners of individual papers to catch in the sensor opening, either stopping the bundle or tearing the papers, with torn paper pieces sometimes blocking the sensor opening and preventing the sensor from functioning properly. Thus, this placement of the newspapers on the conveyor track causes the edges of the newspaper to push into the optical sensor openings in the guiderails. When this occurs, the opening can either grab and retain the paper on the conveying system to cause a jam on the conveyor, or the sharp edges of the opening can actually tear the paper being transported on the conveyor. In either case, the end result is that the conveyor system is not functional.
Traditionally, prior art has attempted to rectify this problem by depressing all edges of the sensor opening or by placing the sensor opening in the center of a tapered or dimpled hole. Each of these attempted remedies have met with only limited success.
The present invention overcomes these and other problems by providing a uniquely configured opening which allows the transport of irregular paper materials while limiting the jamming tendencies and reducing the tendency of the opening to tear the paper on the conveyor system.
Therefore, the present invention resides in a conveyor guiderail snag resistant opening (hereinafter xe2x80x9csnag resistant openingxe2x80x9d) which allows for the passage of irregular materials, such as newsprint and loose paper, to protrude into the snag resistant opening without jamming, snagging, or tearing the loose materials. More specifically, the present invention resides in a sensor opening having a unique configuration which forms a depression in a guiderail of a conveyor system such that stray materials are able to enter and leave the depression without jamming on the conveyor track and without damage to the materials being transported.
The present invention also resides in various embodiments of the above invention where snag resistant openings can be used to prevent damage to irregular materials passing near the snag resistant opening.
Therefore, it is an object of the invention to provide a snag resistant opening manufactured in a unique shape which can be used on a conveying system where cutouts are needed in the guiderails of the conveying system to allow sensors, including optical sensors and infrared sensors, to detect the presence and movement of materials being transported on the conveying system.
Other objects and features of the present invention will be in part apparent and in part pointed out hereinafter.